[Astronouth7303]

Intuitive controls. Even if you have a complex drive system, if you have a simple/intuitive control system your drivers will be able to drive it.
And practice, lots of practice.

Here's an example (idea taken from some bots, controls from an arcade game):
A bot has four wheels. each has its own drive motor. Each can also spin a continuous 360 degrees (Can spin forever without reversing). Complex drive.
On the control side: 2 joysticks. One for the left, one for the right. Each side goes the direction the joystick is pointed. Up means forward, down means backwards, left means left, right means right. U.L. means 45 degrees to the left from forward. The farther from center, the faster it goes. Front/back wheels are linked in code.

This control system is simple, and follows a standard skid-steer setup (with some mods). however, you can translate (go left/right w/o rotating) by pointing the the joysticks that way. So basically, you can make your robot dance, or rotate while moving forward (advanced technique).

Granted, this sort of set-up would take lot's of practice. lots and lots.